Infiniti QX56 (JA60). Manual - part 277

P1810 NEUTRAL-4LO SWITCH

DLN-31

< COMPONENT DIAGNOSIS >

[ATX14B]

C

E

F

G

H

I

J

K

L

M

A

B

DLN

N

O

P

4. Push and release neutral-4LO switch and check continuity

between neutral-4LO switch terminals 12 and 13.

Are inspection results normal?

YES

>> GO TO 5.

NO

>> Replace neutral-4LO switch. Refer to 

DLN-16, "Compo-

nent Parts Location"

.

5.

CHECK TRANSFER CONTROL UNIT

Check transfer control unit input/output signal. Refer to 

DLN-81, "Reference Value"

.

Are inspection results normal?

YES

>> GO TO 6.

NO

>> Check transfer control unit pin terminals for damage or loose connection with harness connector.

If any items are damaged, repair or replace damaged parts.

6.

CHECK DTC

Drive the vehicle and then perform self-diagnosis.
Are inspection results normal?

YES

>> Inspection End.

NO

>> Replace transfer control unit. Refer to 

DLN-130, "Removal and Installation"

.

Component Inspection

INFOID:0000000005148791

1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect neutral-4LO switch harness connector.
3. Remove neutral-4LO switch. Refer to 

DLN-16, "Component Parts Location"

.

4. Push and release neutral-4LO switch and check continuity

between neutral-4LO switch terminals 12 and 13.

5. If the inspection results are abnormal replace the neutral-4LO

switch.

Terminal

Condition

Continuity

12 - 13

Push neutral-4LO switch

Yes

Release neutral-4LO switch

No

SDIA2696E

Terminal

Condition

Continuity

12 - 13

Push neutral-4LO switch

Yes

Release neutral-4LO switch

No

SDIA2696E

DLN-32

< COMPONENT DIAGNOSIS >

[ATX14B]

P1813 4WD SHIFT SWITCH

P1813 4WD SHIFT SWITCH

Description

INFOID:0000000005148792

The 4WD shift switch allows the driver to select AUTO, 2WD or 4WD and 4H or 4LO.  DTC P1813 will set if

more than two switch inputs are simultaneously detected by the transfer control unit due to a short circuit in the

4WD shift switch.

DTC Logic

INFOID:0000000005148793

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

DTC CONFIRMATION PROCEDURE

1. Turn ignition switch ON.

2. Perform self-diagnosis.
Is DTC P1813 displayed?

YES

>> Perform diagnosis procedure. Refer to 

DLN-32, "Diagnosis Procedure"

.

NO

>> Inspection End.

Diagnosis Procedure

INFOID:0000000005148794

Regarding Wiring Diagram information, refer to 

DLN-89, "Wiring Diagram - ALL-MODE 4WD SYSTEM -"

.

1.

CHECK 4WD SHIFT SWITCH SIGNAL

With CONSULT-III

1. Turn ignition switch ON. (Do not start engine.)

2. Select DATA MONITOR mode for ALL MODE AWD/4WD with CONSULT-III.

3. Read out ON/OFF switching action of the 2WD SWITCH, AUTO SWITCH, LOCK SWITCH, 4L SW with

operating 4WD shift switch.

Without CONSULT-III

1. Turn ignition switch ON. (Do not start engine.)

2. Check voltage between transfer control unit harness connector

terminals and ground.

DTC

CONSULT-III

Diagnostic item is detected when...

Reference

[P1813]

4WD MODE SW

More than two switch inputs are simulta-
neously detected due to short circuit of 
4WD shift switch.

Refer to 

DLN-32

.

Connector

Terminal

Condition

Voltage (Ap-

prox.)

E142

9 - ground

4WD shift switch: 2WD

Battery voltage

4WD shift switch: AUTO, 4H or 4LO 0V

18 - ground

4WD shift switch: 4H

Battery voltage

4WD shift switch: 2WD, AUTO or 
4LO

 0V

23 - ground

4WD shift switch: 4LO

Battery voltage

4WD shift switch: 2WD, AUTO or 4H  0V

24 - ground

4WD shift switch: AUTO

Battery voltage

4WD shift switch: 2WD, 4H or 4LO

 0V

WDIA0148E

P1813 4WD SHIFT SWITCH

DLN-33

< COMPONENT DIAGNOSIS >

[ATX14B]

C

E

F

G

H

I

J

K

L

M

A

B

DLN

N

O

P

Are inspection results normal?

YES 

>> GO TO 5.

NO

>> GO TO 2.

2.

CHECK 4WD SHIFT SWITCH POWER SUPPLY CIRCUIT

1. Turn ignition switch OFF. (Stay for at least 5 seconds.)

2. Disconnect 4WD shift switch harness connector.

3. Check voltage between 4WD shift switch harness connector ter-

minal 1 and ground.

4. Turn ignition switch ON. (Do not start engine.)

5. Check voltage between 4WD shift switch harness connector ter-

minal 1 and ground.

Are inspection results normal?

YES

>> GO TO 3.

NO

>> Refer to 

DLN-22, "Diagnosis Procedure"

.

3.

CHECK HARNESS BETWEEN 4WD SHIFT SWITCH AND TRANSFER CONTROL UNIT

1. Turn ignition switch OFF. (Stay for at least 5 seconds.)

2. Disconnect transfer control unit harness connector and the 4WD shift switch harness connector.

3. Check continuity between the following terminals.

-

Transfer control unit harness connector E142 terminal 9 and

4WD shift switch harness connector M141 terminal 2.

-

Transfer control unit harness connector E142 terminal 18 and

4WD shift switch harness connector M141 terminal 5.

-

Transfer control unit harness connector E142 terminal 23 and

4WD shift switch harness connector M141 terminal 6.

-

Transfer control unit harness connector E142 terminal 24 and

4WD shift switch harness connector M141 terminal 3.

Also check harness for short to ground and short to power.

Are inspection results normal?

YES 

>> GO TO 4.

NO

>> Check the following. If any items are damaged, repair or replace damaged parts.

• Harness for short or open between battery and transfer shut off relay harness connector E69

terminal 5.

• Power supply circuit for transfer control unit.  Refer to 

DLN-22, "Diagnosis Procedure"

.

4.

CHECK 4WD SHIFT SWITCH

1. Turn ignition switch OFF. (Stay for at least 5 seconds.)

2. Disconnect 4WD shift switch harness connector. 

Connector Terminal

Voltage 

(Approx.)

 M141

1 - Ground

0V

SDIA2383E

Connector

Terminal

Voltage (Approx.)

M141

1 - Ground

Battery voltage

PDIA0210E

Continuity should exist.

SDIA2699E

DLN-34

< COMPONENT DIAGNOSIS >

[ATX14B]

P1813 4WD SHIFT SWITCH

3. Operate 4WD shift switch and check continuity between 4WD

shift switch terminals.

Are inspection results normal?

YES

>> GO TO 5.

NO

>> Replace 4WD shift switch.

5.

CHECK TRANSFER CONTROL UNIT

Check transfer control unit input/output signal. Refer to 

DLN-81, "Reference Value"

.

Are inspection results normal?

YES

>> GO TO 6.

NO

>> Check transfer control unit pin terminals for damage or loose connection with harness connector.

If any items are damaged, repair or replace damaged parts.

6.

CHECK DTC

Drive the vehicle and then perform self-diagnosis.
Are inspection results normal?

YES

>> Inspection End.

NO

>> Replace transfer control unit. Refer to 

DLN-130, "Removal and Installation"

.

Component Inspection

INFOID:0000000005148795

COMPONENT INSPECTION

1. Turn ignition switch OFF. (Stay for at least 5 second.)
2. Disconnect 4WD shift switch harness connector. 
3. Operate 4WD shift switch and check continuity between 4WD

shift switch terminals.

Terminal

Condition

Continuity

1 - 2

4WD shift switch: 2WD

Yes

4WD shift switch: AUTO, 4H and 
4LO

No

1 - 3

4WD shift switch: AUTO

Yes

4WD shift switch: 2WD, 4H and 
4LO

No

1 - 4

4WD shift switch: 2WD

No

4WD shift switch: AUTO, 4H and 
4LO

Yes

1 - 5

4WD shift switch: 4H

Yes

4WD shift switch: 2WD, AUTO, 
and 4LO

No

1 - 6

4WD shift switch: 4LO

Yes

4WD shift switch: 2WD, AUTO and 
4H

No

WDIA0205E

Terminal

Condition

Continuity

1 - 2

4WD shift switch: 2WD

Yes

4WD shift switch: AUTO, 4H and 
4LO

No

1 - 3

4WD shift switch: AUTO

Yes

4WD shift switch: 2WD, 4H and 
4LO

No

WDIA0205E